released by Fulham in July 2017. Coventry City Grimmer signed a two-year contract with newly relegated League Two side Coventry City in July 2017. He was named as the division's Player of the Month for September. On 6 January 2018, he scored the winning goal from long-range in Coventry's 2–1 victory over Premier League side Stoke City in the Third Round of the FA Cup. He went on to be named on the PFA Team of the Year for the 2017–18 campaign as he helped Mark Robins's "Sky Blues" qualify for the play-offs. Coventry then eliminated Notts County in the play-off semi-finals, before Grimmer scored the third goal in a 3–1 victory over Exeter City in the play-off final at Wembley Stadium. However he was limited to just 13 appearances in the 2018–19 season and admitted that "Last season was a dream, but the difference between that and this season has been like night and day." He was released from the Ricoh Arena on 9 May. Wycombe Wanderers On 22 July 2019, Grimmer signed a two-year contract with League One club Wycombe Wanderers after impressing manager Gareth Ainsworth on trial. He later said it was an unpleasant experience to spent over two months as a free agent, but that "holding off for the right club was absolutely the right decision for my happiness and my enjoyment of the game" and he was "very, very thankful that I am where I am now". He was limited to 18 league appearances during the 2019–20 season, which was settled on points per game (PPG) due to the COVID-19 pandemic in England; Wycombe finished third on PPG. He went on to start all three play-off games, as Wycombe secured a place in the Championship after beating Oxford United in the behind closed doors Wembley final. His fiancée, Sammy, speaking two weeks later said that "I'm so proud of him and Jack won't let his winner's medal out of his sight – he even took it on holiday with us and we had to keep it in the safe at the hotel". He signed a new three-year deal with Wycombe in August 2020. Wanderers took their battle against relegation to the last day of the 2020–21 Championship season, but ultimately occupied the final relegation spot. Grimmer finished third in the Supporters' Player of the Year award nominations, as voted for by fans online. He scored